What causes melasma? The cause of melasma is complex. The pigmentation is due to overproduction of melanin by the pigment cells, melanocytes, which is taken up by the keratinocytes (epidermal melanosis) and/or deposited in the dermis (dermal melanosis, melanophages).
There are five total papillary muscles in the heart; three in the right ventricle and two in the left. The anterior, posterior, and septal papillary muscles of the right ventricle each attach via chordae tendineae to the tricuspid valve. The anterior and posterior papillary muscles of the left ventricle attach via chordae tendineae to the mitral valve.
Making the world better, one answer at a time. Cardiac muscle tissue forms the bulk of the wall of the heart. Smooth muscle tissue is located in the walls of hollow internal structures such as blood vessels, the stomach, intestines, and urinary bladder. Skeletal muscle tissue is named for its location-attached to bones. Skeletal muscles are found attached to the bones, which enables their movemen.t.